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Using the ONLIDX_MAXMEM Configuration Parameter Before Creating Indexes Online

The ONLIDX_MAXMEM configuration parameter limits the amount of memory that is allocated to a single preimage pool and a single updator log pool. The preimage and updator log pools, pimage_<partnum> and ulog_<partnum>, are shared memory pools that are created when a CREATE INDEX ONLINE statement is executed. The pools are freed when the execution of the statement is completed.

The default value of the ONLIDX_MAXMEM configuration parameter is 5120 kilobytes. The minimum value that you can specify is 16 kilobytes; the maximum value is 4294967295 kilobytes.

You can set this configuration parameter in the ONCONFIG file before starting the database server, or you can change it dynamically through the onmode -wf and onmode -wm commands.

If you specify a value for this parameter and then create a table, add rows to the table, and start to execute a CREATE INDEX ONLINE statement on a column, you can also perform other operations on the column, such as running UPDATE STATISTICS HIGH, without having memory problems.

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